Two-step knife-switch.



W; 11111111111111), JR. 7 TWOSTEP KNIFE SWITCH.

APPLICATION FILED APR. 26, 1911.

1,005,060, v v Patented Oct. 3, 1911.

WITNESSES: //v VE/V TOR UNITED STATES PAll-ENI-QFF E- WILLIAM MUIRH'E A an, on NEW YORK, n. Y.

TWO-STE]? KNIFE-SWITCH.

- Specification of Letters Patent.

' Patented Oct. 3, 1911.

Application filed April 26, 1911. Serial No.'62 3,523.

fication. I

My invention relates to knife switches used for motor control.

The objects of my invention are, first,

to shunt the motor-running fuses during the starting-current period; and, second, to maintain the circuit continuous during the change from the starting step to the running step.

In the drawings accompanying and form- ..ing part of this specification, and in the description of the drawings, I have shown my invention in its preferred form, and have shown what I deem to be the best mode of applying the principles thereof; but it is'to be understood that, within the scope of the appended claims, I contemplate changes in .form, proportions, and materials, the trans position of parts, and the substitution of equivalent members, without departing from the spirit of my invention.

Figure 1 is a front elevation of a switch made in accordance with the principles of my invention. Fig. 2 is a side elevation, showing one method of mounting, and showing the blade in dotted outline in starting position and in full outline in running position. Fig. 3 is a cross section on a plane indicated by the line A-A in Fig. 1,.

Similar reference characters indicate like or corresponding parts throughout the several views.

a is the base, made of any suitable material, shape, and size, on which the several parts are mounted;

c is a lug to which the wire or other conductor is connected, the current passing thence through a plate a, the fuse (Z, plate'b, standard 9 and to the blade 6, which is pivoted to the standard. Plates a and Z) are merely convenient electrical connections; and the fuse (Z is of sufficient carrying capacity for motor inrush current. The contact springs f, mounted on the plate 72., are spread farther apart in their lower section, as shown at f, than in their upper section where they are adapted to engage the blade, so that the initial closing movement of the blade will common handle to.

make electricahconnection with the contacts and the further and completeclosing movement will leave the; blade out of contact therewith. The wire or conductor may be connected with the plate 71. through the terminal lug p. The jaw or contact springs g, g are mounted on the copper strip. Z, which is mounted on and insulated from the base, as by means of the insulation 2' and insulating'bushingsm, n. This jaw is'ada'pted to engage the blade after its intial engagement with the contacts f.. -The parts are so an ranged with relation to each other that on initial closing movement, that is, the first step, the contact is formed between theblade and the contacts f, on further movement, and before the blade is out of contact f,the

on still further movement, contact is broken at f, and maintained at g, this constituting the second step; the circuit remaining continues through the switch while the'blade is moved from the first to the second step. The fuse clip I? is mounted on the strip Z and insulated from the strip or plate 71.. The fuse'clip 71' is mounted-on and electrically connected with the strip h. The fuse s is mounted between the two clips.

Itwill now be understood that during the first step, the current will. pass through the fuse (Z; that during the second step it will pass through the fuse s; and that it will be maintained continuously while theblade is passed from first to second step.

In actual use I contemplate that the fuse" (Z shall be of greater carrying capacity than blade makes contact with the jaw g; and r fuse s, that fuse. d shallbe of sufiicient carrying capacity for motor inrush current;. and that the capacity of fuse 5 shall be limited to the necessary running current.

In the drawings I have shown two switches, the blades being provided with a But the invention may be applied to any number, one or more, to switches of any number of poles, and either front or back connected. Vhat I claim is: 1. The combination of a base, two fuses of different carrying power mounted thereon, a blade pivoted thereon, two contacts mounted thereon and so arranged with relation to the blade that on initial movement of theblade in closing said blade will connect with one of said contacts without connecting with the other contact, that on further and final closing movement said blade will connect-With the other contact and be disconnected from the first contact, and that it will be connected with both contacts. in passing from the initial position to its final position; electrical terminals mounted on the base; and electrical eonnectors connecting one of said, terminals with one of said tuses connecting said use with the switch blade, connecting the initial contact- 'with the other terminal, connecting the second contact with the other tuse and connecting said other fuse with said other terminal; whereby on initial movementct the switch the current is shunted around said second-named fuse. a i

2. The-combination of a base, two fuses of different carrying power mounted on the face thereof, a blade pivoted on the face thereof, two contacts mounted on the face.

thereof and so arranged with relation to the blade that on initial closing movement ot the blade'said blade will connect with one of said contacts without connecting with the other, that on further and final closing menace-o 'movement said blade will connect with the other contact and be disconnected from the first Contact, and that it will be connected cal terminals mountedon the face oi the base; and electrical connectors connecting one of said terminals with one of said fuses, connecting said fuse with the switch blade, connecting theinitial contact. with the other terminal, connecting the second contact with the other fuse, and connecting said other fuse with said other terminal; whereby on initial closing movement of the switch blade the current is shunted around said secondnained fuse.

Signed at New York city in the county of New York and State of New York this 20th day of March A. D. 1911.

"WiLLiAM noinnniin, JR.

Witnesses:

JOHN AsnMnAn, FRANK Gnoneio'.

' Gopies of this patent may be obtained for five cents each, by addressing the Commissioner 'of l atents,

Washington, D. Q. 

